Di-substituted beta-phenethylcarbbamic acid esters

ABSTRACT

Novel di-substituted Beta -phenethylcarbamic acid esters. The compounds are useful as antidepressants and anti-Parkinsonism agents.

United States Patent [191 Biel et al.

[451 Feb. 4, 1975 DI-SUBSTITUTED 1 BETA-PHENETHYLCARBBAMIC ACID ESTERS [75] Inventors: John Hans Biel, Lake Bluff, lll.;

Irwin L. Klundt, Brookfield, Wis.

[73] Assignee: Aldrich Chemical Company,

Milwaukee County, Wis.

22 Filed: Aug.2, 1973 21 Appl. No.: 385,008

Related U.S. Application Data [62] Division of Ser. No. 96,586, Dec. 9, 1970, Pat. No.

32] U.S. Cl 260/47! C Int. Cl. C(l7c l25/06 Primary ExaminerLorraine A. Weinberger Assistant Examiner-L. A. Thaxton Attorney. Agent, or Firm-Robert L. Niblack; Joyce R. Krei; Vincent A. Mallare [57] ABSTRACT Novel di-substituted B-phenethylcarbamic acid esters. The compounds are useful as antidepressants and anti- Parkinsonism agents.

4 Claims, No Drawings Dl-SUBSTITUTED BETA-PHENETHYLCARBBAMIC ACID ESTERS CROSS REFERENCE TO RELATED APPLICATIONS This is a division of application Ser. No. 96,586, filed Dec. 9, 1970, now U.S. Pat. No. 3,801,624, issued Apr. 2, 1974.

BACKGROUND OF THE INVENTION Until recently, patients suffering from Parkinsonism were treated with anticonvulsants, antispasmodics, central nervous system stimulants. and the like, in an attempt to produce temporary amelioration of their complaints. In severe cases, surgical procedures were employed with some success. L-Dopa was the first single agent found to be effective in reversing the akinesia and rigidity of Parkinsonism, particularly in severe cases. An increase in mental alertness and wakefulness, relief from depression, and an increase in intellect has also been observed in patients receiving L-Dopa.

While L-Dopa has produced some rather promising results in experimental therapy and is being used in a limited number of patients, it is not well tolerated by a number of patients. The most frequent side effects are nausea, vomiting, postural hypotension, cardiac dysrhythmia and choreiform movements. The abnormal, involuntary movements pose severe problems to the drugs continued use in approximately 50% of the patients. Furthermore, dopamine itself it not orally active and has a very short duration of action. Thus, the search for more effective, orally-active, long-acting anti-Parkinson agents continues. It is an object of the present invention to provide such agents.

SUMMARY This invention relates to novel (ii-substituted B-phenethylcarbamic acid esters represented by the structural formula:

. ll R 0 l cu -cu -uuc-oa 2 wherein:

R and R are hydrogen, benzyl, substituted benzyl,

wherein A is O, NH, or S, and R is lower alkyl, lower alkenyl, or lower alkynyl; and R is lower alkyl, lower alkenyl, lower alkynyl, lower haloalkyl, cyclopropylmethyl, ,B-(2-furyU-ethyl or azetidinyl; with the limitation that when A is O and R is ethyl, R cannot be ethyl, and when R and R are benzyl, R cannot be methyl.

The presently preferred compounds for treating Parkinsonism are those wherein R, is hydrogen or benzyl; R is hydrogen or benzyl; and R is ethyl or trichloroethyl, and A is O.

The term lower alkyl as used herein refers to both straight and branched chain C -C5 alkyl groups including methyl, ethyl. n-propyl, iso-propyl, n-butyl, sec- 2 butyl, tert-butyl, iso-butyl, n-pentyl, iso-pentyl, neopentyl, and the like.

Lower alkenyl refers to both straight and branched chain alkenyl groups containing from 2 to 5 carbon atoms, such as vinyl, allyl, methallyl, l-pentenyl, and the like.

Lower alkynyl" refers to C -C5 alkyl groups as defined above from which two hydrogen atoms have been removed from each of two adjacent carbon atoms to produce acetylenic unsaturation; e.g., propargyl, 2- butynyl, l-pentynyl, and the like.

Substituted benzyl" refers to a mono-, di-. or trisubstituted benzyl moiety substituted in the ortho, meta and/or para positions by a chloro, fluoro, iodo, bromo, or tri-fluoromethyl atom.

Halo" includes chloro, fluoro, bromo, and iodo.

The anti-Parkinson activity of the above compounds was established using the Harmonyl (deserpidine) Antagonism Test. In the Harmony] test, mice was closed orally with 50 mg/kg of deserpidine 24 hours prior to drug evaluation. In mice, deserpidine produces ptosis, hunched posture, sedation, catalepsy and rigidity. L- Dopa produces marked reversal of the above effects in mice. Antagonism of the deserpidine effects in mice are graded slight (1), moderate (2) or marked (3), based on the reversal of the Harmonyl effects. The compounds of the invention produce moderate to masked reversal in dosages of from 10 to 200 mg/kg of body weight.

The compounds are generally administered to mammalian Parkinsonism patients in dosages of from 10 to 200 mg/kg of body weight daily, preferably in divided doses. While the compounds exhibit both oral and parenteral activity, the preferred route of administration is the oral route. The oral LD of the compounds of this invention in mice are approximately 600-]000 mg/kg.

The antidepressant activity of the compounds of this invention was first established in the modified dopa test as described by Everett et al., Fed. Proc., 23 p. 198 (1964). The compounds are useful as antidepressant agents when administered to depressed patients in dosages of from 10 to 200 mg/kg of body weight daily, preferably in divided doses.

Representative compounds of the present invention include acid, 3-

' 3 I f 4 3,4-Dimethoxycarbonyl-B-phenethylcarbamic acid, tered, and solvent removed in vacuo and the residue methyl ester purified by a Kugel'rohf' distillation to give 14 g 3. p pa gy y a ny -B-p y 78%) of 3,4-dibenzyloxy-B-phenethylisocyanate as a acid. p p y ester. light yellow oil, b.p. 180 0.05 mm). 3,4-Diallyloxycarbonyl-B-phenethylcarbamic acid, 5

ally] ester 7 The method of synthesis of the compounds of this in- Analysis Calcd. for C H NQ: C, 76.86; H, 5.89; N, 3.90 ventlon IS represented by the following reaction 11 2 C 7M7; H.175; N 3.90 scheme.

RC1 011 x no@-cao no no R n-cn-no no R0 R0 u I 110i .cn -cn -naco n' pu Ho O a 2 no cn -cn -nnco a m cn -ca -an Muv or angel I 'Qy ll mco:@ cn -cn -nn co it RACQ ROQ-CH -CH -N-C-O o I R0 Generally sp king. protocat h l ehyd (Ald- B. 3,4-Dibenzyloxy-B-phenethylcarbamic acid, isoprorich Chemical Co.) is reacted with RC] (i.e. benzyl pyl ester chloride, etc.) to prepare 2-(wherein R=C H5CH 40 [n a 50 fl k i d ith a magnetic stirrer and 2 coflvened to ,thefiofrespondlng Q Y 3, a reflux condenser protected by a drying tube were which treated with lithiumalummum hydride and the placed 45 g 5 mole) f 3 4 ib l firesulting amine 4 reacted with an appropriate chlorophe'nethylisocyanate ml f benzene, 3 ml f dry formate to prepare 5 (R=loweralkyl, etc.) or the iso propanol and a crystal of blcyclo [2,2,2] 1,4- amme 4 can be convened to the lsocyanate 8 and diazaoctane. The reaction was heated at reflux for 20 ifzs i ytg i z r aliohol to preparg hours. Removal of the solvent left a residue which conwhic? can be zf g g fiiig fig g g tained the unreacted isocyanate. The residue was redising 6 with either an appropriate chloroformate or an solved 25 ml of benzene of lsoljmpalnol isocyanate added with 2 drops of DBU (Ardr1ch-l,3-dlazab1cycl0[5,4,0]undec-5 ene) added. This was heated to re- Thfll' lfth'llttth t e 0 owmg examp es ur er] us m e 8 press flux for 24 hours. The reaction was cooled,diluted with invention.

25 ml of benzene, filtered and the solvent was removed in vacuo. The residue was dissolved in 150 ml of hot cy- EXAMPLE I clohexane and set aside to crystallize. The white solid PREPARATION OF was filtered off and dried in vacuo to yield 2.1 g of 3,4- 3.4-DIBENZYLOXY-B-PHENETHYLCARBAMIC dibenzyloxy-B-phenethylcarbamic acid, isopropyl es- AClD, ISOPROPYL ESTER tel-9 8() 83C,

A. 3,4-Dibenzyloxy-flphenethylisocyanate a 500 ml three necked flask q pp with a 2 Analysis Calcd. for C .,H,1NO c. 74.44; H, 6.97; N, 3.34 inlet tube and a Claisen head for distillation were Found: .8 1

placed 18.5 g (0.05 mole) of benzyloxydopamine hydrochloride in 350 ml of toluene. This was heated to 65 reflux and ml of toluene distilled off. The Claisen EXAMPLES 2 9 head was replaced with a reflux condenser equipped with a drying tube and phosgene was bubbled through The following compounds were prepared according the refluxing solution for four hours. The reaction was to the method of Example 1 by replacing isopropanol allowed to stand at room temperature overnight, fllwith the appropriate alcohol.

H RIO cH -ca -Nnc-oR Mi l i i Ex. Empirical m m NO. R1 R2 R4 in. 1 066616 c H N c ll n 2 n cap cn 91.5-92.5 c a uo 60.25 7.11 5.86 60.13 7.23 5.77 a CC13CHZ 155 -157 c u cl uo 40.21 3.68 4.12 40.46 3.84 4.14 4 a a A411 11a 119 CUHUNOZ 62.07 6.81 5.57 62 20 .51 5.59 5 H H o D- I 102 104 CMHNNOI. 63.42 7.7 5.23 63.40 7.99 5.71 6 a c n cc 11 127 129 c n uo 56.64 6.40 4.71 56.71 6.44 4.60 7 6 11 011 CGHSCHZ cn rct 127.5-12s.s c u cluo 59.01 4.75 2.75 59 16 4.63 2.88 a c a ca C l'l CH CH(CH3)2 so 83 c n no 74.44 6.97 3.34 74.68 6.89 3.41

I 9 c u cn c n cn 68 71 73 11 110 73.36 6.11 3.06 73.36 5.97 3.1

servin wettin emulsif in and dis ersin a ents. EXAMPLE g y g p g g 3,4-DIHYDROXY-B-PHENETHYLCARBAMIC ACID, ETHYL ESTER A solution of 45 g of 3,4-dibenzyloxy-B-phenethylcarbamic acid, ethyl ester, prepared according to the method of Example 1, in 200 ml of ethanol containing 3 g of moist 10% Pd/C was hydrogenated at 40 p.s.i. The reaction was filtered, evaporated to dryness and recrystallized from benzene to yield 18.4 g of product, m.p. 99l0l.

Analysis Calcd. for C H 5NO I C. 58.65; H, 6.71, N, 6.22 Found: C. 58.63; H, 6.58. N, 5.98

The compounds useful in the practice of the present invention are generally formulated into pharmaceutical compositions comprising, as an active ingredient, at least one of the active agents in association with a pharmaceutical carrier of diluent. The compounds useful in the practice of the invention exhibit both oral and parenteral activity and can be formulated in dosage forms for oral or parenteral administration.

Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, and elixirs containing inert diluents commonly used in the art, such as water. Besides inert diluents, such compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents and sweetening, flavoring and perfuming agents.

Preparations according to this invention for parenteral administration include sterile aqueous or nonaqueous solutions, suspensions or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and injectable organic esters such as ethyl oleate. Such dosage forms may also contain adjuvants such as pre- They may be sterilized by, for example, filtration through a bacteriaretaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. They can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.

The dosage of active ingredient in the compositions of this invention may be varied; however, it is necessary that the amount of the active ingredient shall be such that a suitable dosage form is obtained. The selected dosage depends upon the desired therapeutic effect, on the route of administration, and on the duration of the treatment.

We claim:

1. A compound of the formula R being loweralkyl, loweralkenyl or loweralkynyl; R is 9 -CNHR3 and R is loweralkyl, loweralkenyl, loweralkynyl, lowerhaloalkyl or cyclopropylmcthyl, with the limitation that each R cannot be ethyl when R, is ethyl.

2. A compound in accordance with claim 1 wherein R, is H, R is 3. A compound in accordance with claim 2 wherein each R and R are loweralkyl.

4. A compound in accordance with claim 3 wherein R and R each are ethyl. 

1. A COMPOUND OF THE FORMULA
 2. A compound in accordance with claim 1 wherein R1 is H, R2 is
 3. A compound in accordance with claim 2 wherein each R3 and R4 are loweralkyl.
 4. A compound in accordance with claim 3 wherein R3 and R4 each are ethyl. 